Chemical feed pump mechanism



June 18,1946. v J, CORYD N, D 2,402,524

CHEMICAL FEED PUMP MECHANISM Filed April '6, 1944 a INVENTOR,

H6 2 BY ATTORNEY Patented June 18, 1946 tea es! CHEMICAL EE'ED PUMl woman I Jeff CorydpnLII; Gnanstom; Rzs'lslassiz-nonllto, r i' Morse Boulgen-llestructor comnemniazcn mrae i q tion 02- Delaware Application April 6, 1944, serial Nd 529,929

' The present invention relatesto fluid-processing systems and arrangements; and} has particular reference to anovel-pnmp mechanism therefor... ..V i

Theprincipal objectot the invention isto pro vide a; chemical feed pump mechanism whi'c'ir is particularly designed for high speed-operation. Another object of 'the invention is t'o" provide a chemical feed pumpof the-sea lsheet -ty-pe which combines the positive displacement action ii-Claims. (o1. line-1,53

of api'st'on type puI-np with the leak-proof characteristics of a packing gland -less-diaphragm purnp L. y i l V 7 ll":

Still another object of the-invention is to provide a ieed pump ofi the' type describedwhich is immune to corrosive-or-other deteriorating chernicalsanel hasextremely long life,

A further-object is to provide a novelcheck high's'peed pump-operation; 4

valve construction for preventing 'val velagin =With the above and= other objectsand advan- J tageoi-is features-in view; the invention consists of a novel'ar'rangement of-pa rts more fullydisclosed in the detailed descriptionfollowing, lnconilunction witlrthe accompanying drawing; and more specifically defined in the claims appended jtheret 1y V, i i .W ,2. In the drawing, 7

Fig. l is a top. plan view ofthenovel-feed pum-p mechanism; and i Fig; 2 1s a-ver-ticalsection on the liri--l-Z of -=It* has been founddesirable toprovide a very compact light weight pumping mechanism for pumping chemical's' for fluid processing such as the hypochlorination of water supplies by thead-- I ditionef' calcium hypochlorite' orsodium-hypochlorit'e measured quantities. "The pump mechanism must "be resistant to the pumped chemicals and the pump parts must be simple in structure and positive in operation and have'long 1; a

' ed, the upper portion i! being bored to receive a bushing l8 in which the piston pump rod 19 is slidingly received, and the lower porti'onZU of the cap being sufilciently large to house the upper end 2 l' of the piston M; this upper end being reduced 1nthiokness 'anddnternally bored and threaded t'o recei-vethe correspondingly reduced a-n'd threade d endportion 220i thepistonrod';

Aflextble'seal sheet2'$ ismounted between the cylindep and its. canand islockedin-placeby the I can and cylin'dep bolts 2E, the seal sheet having a central opening 25 which seats over the upper-end 21: of the-ptston-andibeing cIamped-to-the piston bya l'ock washer -23 and a lock nut 21 which threadedl'y engages-the correspondingly threaded outer surface-oi theupper'piston end'2 i -'I he pump cylihder'is 'provided 'witha lateral outlet passage 28 which; freely communicates with th pump chamber I462 The piston-Hi ls pref erably ofi the cylindrical'disk type to obtain accurate 'f'eed volumes; and: fits withinthelwall's of V the cylihder bore-13.; iAny air-accumulated inthe space between the'piston and theseal sheet acts asa 'damping 'device' or a dashpot, with resultant interference with the accuracy. of feed: volumes an-d possible stoppage-of-the-pumping action because: of the-alternate compression orexpansion of the trapped-air. Anal-r duct or vent 29 is thereforeprovided at;- thetopporti'on ofthepump cylinder tol 'communicate the upper portion betwee'ir the piston andthe seal sheet with the cut let passage 28- and eject orrelease any accumulated-air: V

Thezba'se I2 has a depending boss'fili to which aninlet nipple- 34 attached; b thread-ing, for conveying treatment fluid to a vertical i-nflow passage- 32which. communicates with a conical inlet chamber 31t. Av check valve: 34' is positioned in -the inlet .cl'i'amber-- with its Valve disk 33 adapted to seat on. the-conical. walls 35 of the inlet "chambel which formia valve-seat, the valvestem 37 of-th'e oheck valve-depending downwardly into the vertical inflow: passage. 32 ,-whi'ch acts as a guide for the valve stem The disk edgeSS is preferably of rubber oratherresilient and chemically resistant material, secured'to the periphery of the disk in any suitable manner, and the valve disk is provided with a central upstanding abutment or projection 35 which is positioned directly in the path of the piston movement. The use of the upstanding abutment reduces the clearance between the lower surface of the piston and sage 4| communicating with the pump cylinder outlet passage 28 and leading to a vertical passage 42 for conveying the treatment fluid to an outflow chamber 43. A valve seat 44 is positioned in the outflow chamber over the upper portion of the vertical passage 42, the valve seat being referably of rubber or similar resilient and chemical resistant material, and a check valve 45 is mounted in the casing with its valve head 46 adapted to engage the preferably conical walls 41 of the valve seat, the stem 48 of the valve extending through the central opening 49 of the valve seat and depending into the vertical passage 42, which acts as a valve'stem guide.

A valve loading disk 50 is provided with flow passages 5| and is threaded or otherwise secured to the inner walls of the outflow chamber, and

a closure top 52 is threaded into the upper portion of the outflow chamber, the closure top having a flow opening 53 which communicates with the flowrconduit 54 of an outflow nipple 55 which is threaded into the upper portion of the closure top. The valve loading disk ensures valve closing even if no back pressure is available to seat the outlet check valve, and thus provides proper operation even when feeding into negative pressures.

The improved piston pump mechanism is particularly suitable for constant stroke length operation at variable high speeds, from 150 strokes per minute up. At such speeds the parts must be. light in weight and yetpositive in action; to this end the valve parts are preferably made of condensation products, resins, and the like.

Preferably the pump parts are made of transparent material,so that the flow of treatment chemical may be seen and followed at alltimes, and areof simple construction to permit rapid separation for cleaning, repair and replacement.

Accurate and quick feeding of chemical is ensured by the light weight inlet valve, which moves in exact correspondence with the piston movement, and which has a resilient rim engaging the valve seat, the outflow check valve seating on a resilient seat. Further, all entrapped air above the piston is released to,th e outfl0w passage. These structural .features provide a very accurate and uniform feed. As shown in the drawing, thefiow passages are arranged for direct flow to the fullestpossible extent and eliminate all labyrinth passageways, thus reducing the burden on the pumping mechanism. While I have described a specific constructional embodiment of the invention, it is obvious that changes in the size, shape and material of the pump parts, and in their relative arrangement, may be made to suit the requirements for difierent chemical feeding systems, without departing from the spirit and the scope of the invention as defined in the appended claims.

I claim:

1. A pump mechanism for chemical feeding, comprising a cylinder, a cap and a base, a piston movable in said cylinder, a piston rod for said piston slidably guided in said cap, a flexible seal sheet mounted between said cap and saidcylinder and secured to said piston, said base having an inflow chamber, an inlet check valve in said inflow chamber for controlling passage of fluid to said cylinder, and outlet passage from said cylinder, a casing having an outflow chamber positioned adjacent said cylinder, a passageway in said casing communicating said outlet-passage and said outflow chamber, and an outlet check valve in said casing for controlling passage of fluid from said outflow chamher.

2. Inthe structure of claim 1, said cylinder having a relief duct communicating the cylinder space between said seal sheet and piston with the cylinder outlet passage.

3. In the structure of claim 1, said inlet check valve being positioned in the path of movement of the piston andhaving an abutment extending therefrom for limiting its lift and expediting the valve closure.

4. In the structure of claim 1, said inlet check valve having means associated therewith for limiting its lift.

5. In the structure of claim 1, said outlet check valve having means associated therewith for providing a pressure thereon.

6. A pump mechanism for chemical feeding, comprising a cylinder, a cap, and a base, a piston movable in said cylinder, a piston rod for said piston slidably guided in said cap, a flexible seal sheet mounted between said cap and said cylinder and secured to said piston, said base having an inflow chamber, an inlet check valve and a cooperating valve seat in said inflow chamber, one of the engaging faces of said inlet check valve and its valve seat being made of rubber, an outlet passage'from said cylinder, said cylinder having a relief duct communicating the cylinder space between said diaphragm and piston with said outlet passage, a casing [having an outflow chamber positioned adjacent said cylinder, said casing having a passageway communicating the outlet passage and theuout- JEFF CORYDON'," II. 

